This application claims priority to Great Britain Patent Application No. 0005883.4, filed on Mar. 13, 2000.
The present invention related to electroplating apparatus and a method of electro-plating.
In a conventional electro-plating process, the object to be plated is immersed in a bath of electrolyte together with, but not touching, one or more pieces of the metal with which it is to be plated. Connections are made to a source of electrical current such that the item to be plated becomes the cathode and the pieces of metal become the anode. When an electric current is supplied, ions flow towards the cathode and are reduced thereon to give a coating of the metal from which the anodes are made.
In another electro-plating process, described in International Patent Application No. W99/52336, conductive tracks are provided on a printed circuit by use of a toll having an absorptive member carrying a plating solution.
According to the present invention, there is provided electro-plating apparatus comprising a cathode connector for contact with a substrate onto which material is to be deposited, wherein the cathode connector has means to contact a plurality of discrete regions extending across the width of the substrate and normal to the direction of movement of the substrate and not in the plane of the substrate.
According to the present invention, there is also provided electro-plating apparatus comprising an elongate connector cathode for movement relative to a substrate on which material is to be deposited, the cathode connector having a main body section lying along the longitudinal axis of the cathode connector and at least one projection which extends away from the main body section.
In this way, apparatus of the invention may ensure that electrical contact is maintained with portions of the substrate which would be otherwise electrically isolated from the main body of the substrate.
The present invention may include any one or more of the following preferred features:
the cathode connector comprises a comb-shaped element having an elongate body and at least one tooth extending away from the main body section towards a locations for a substrate on which material is to be deposited, to contact in use a portion of the substrate.
at least one tooth is flexibly biased towards a location for a substrate on which material is to be deposited.
the tooth or teeth comprised an end portion inclined, relative to the reminder of the tooth, in a direction towards a location of the substrate to provide flexible bias towards a location for a substrate on which material is to be deposited.
the cathode connector comprises a roller having at least one disk extending away from the roller towards a location for a substrate on which material is to be deposited, to contact in use a portion of the substrate.
the cathode connector is formed of copper, or beryllium copper, or phosphor bronze, or stainless steel, or any other material with the required electrical and mechanical properties.
means to pass a substrate, onto which material is to be deposited, over the cathode the length of which extends a substantial part of, or all, the width of the substrate.
an electro-plating bath into which the substrate is immersed for deposition of material.
the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrate before entering the bath.
the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrate after leaving the bath.
cleaning means to remove electrolyte from the substrate downstream of the cathode connector.
cleaning means to remove electrolyte from the substrate upstream of the cathode connector.
at least one nozzle means to direct cleansing fluid towards the substrate.
electroplating means to effect dry plating of material onto a substrate.
a tool having an absorptive member to carry plating solution.
the electrode comprises a plurality of teeth or discs, one or more to contact electrically with a separate region which is isolated from other regions of the substrate on the substrate.
the teeth or discs are adjustably spaced along the main portion.
The present invention provides an electroplating method to deposit a material onto a substrate, the method comprising applying a cathode connector to contact with a plurality of discrete regions extending across the width of the substrate and normal to the direction of the movement of the substrate and not in the plane of the substrate.
The present invention may also provide an electroplating method comprising moving an elongate cathode connector relative to a substrate on which material is to be deposited, the cathode connector having a main body section lying along the longitudinal axis of the cathode connector and at least one projection which extends away from the main body section.
The method may include any one or more the following preferred features:
passing a substrate, onto which material is to be deposited, over the cathode connector the length of which extends a substantial or part of, or all, the width of the substrate.
immersing the substrate, onto which material is to be deposited into an electroplating bath containing electrolyte.
passing the substrate over the cathode connector located adjacent to the path of a substrate to contact the substrate before entering the bath.
passing the substrate over the cathode connector located adjacent to the path of a substrate to contact with the substrate after leaving the bath.
cleaning the substrate downstream of the cathode connector to remove electrolyte.
cleaning the substrate upstream of the cathode connector to remove electrolyte.
effecting dry plating of material onto a substrate.
Apparatus or methods of the present invention as described herein may provide the following advantages:
effective electroplating of isolated regions (i.e. not connected with one another) of the substrate is ensured.
effective electro-plating is achieved even for highly-flexible substrates.
effective electro-plating is achieved even for substrates having very roughened surface.
The invention is applicable to electro-plating processes including, but not limited to, those as described hereinabove.